Field of the Invention
The present invention relates to an oxygen barrier coating composition and a method of preparing the oxygen barrier coating composition.
Discussion of the Related Art
Two types of polymers are currently known to give good oxygen barrier coatings. They are chlorinated polymers and poly (vinyl alcohol) (PVA) or ethylene/vinyl alcohol copolymers (EVOH). Chlorinated polymers, such as polyvinylidene chloride (PVDC), are under increasing regulatory pressure, especially when it is necessary to incinerate films made from chlorinated polymers for disposal. Thus it would be desirable to replace chlorinated polymers with non-chlorinated polymers. Polymers and nano-composites based on PVA or EVOH give oxygen barrier properties at low relative humidity, but exhibit high oxygen transmission rates at relative humidity higher than 75%. This deficiency has limited the effectiveness in climates such as those found in the southern United States.
There are currently no commercially available, high speed in-line of printable or coatable, non-chlorinated, one component transparent barrier coatings that give good oxygen barrier—especially above 75% relative humidity. There is need to develop coating compositions that have excellent oxygen barrier properties at relative humidity higher than 75% and do not have significant concentrations of bound chloride. These resins enable solvent-borne coatings, which can be printed, for example, at high speed on a gravure or flexo press or even using the coating station of a laminator.